scher



L. S. SCHER.

TELEPHONE MUFFLER.

APPLICATION nuzn APR.21, I921.

Patented Dec;

' UNITED STATES LOUIS S. SCHER, OF NEW YORK, N.

PATENT OFFICE.

TELEPHONE-MUFFLER.

Specification of Letters Patent.

Patented Dec. 6, 1921.

Application filed April 21, 1921. Serial No. 463,190. a

To all whom it may concern Be it known that I, LoUIs S. SCHER, a citizen of the United States, and resident of New York city, in the county of Bronx and State of New York, have invented certain new and useful Improvements in Telephone- Mutflers, of which the following is a specification.

The invention relates to a telephone muffier, that is an attachment for telephone mouthpieces comprising a member having an opening with which the opening of the mouthpiece communicates and another opening into which the user of the telephone speaks. The device is adapted to enable the user of the telephone to hold private conversation at his desk without being overheard in the same room, and it also is adapted to prevent foreign noises or sounds, such as the rattle of a typewriter or the like, from being transmitted by the telephone. It may, therefore, be said in a general way that the invention performs the functions of a telephone booth, while at the same time it comprises merely a simple attachment for an ordinary telephone transmitter which may very readily-be placed in position and removed therefrom.

The effects referred to are obtained by the provision of a mouth opening into which the voice of the user ma be directed in such a. manner as to exclu e foreign sounds "to a considerable extent, the device having an interior space which comprises a passageway between the mouth opening and the mouthpiece opening. The device is also constructed in such a manner as to prevent toa con-g siderable extent reflection of sounds .from. the inner surfaces of the chamber or member; into which the person u'sin the telephone speaks, so that the articulation of the" voice as transmitted by the telephone will be considerably improved. This effect is obtained by providing walls or surfaces within the.

interior of the device which are so constructed as to absorb, sound waves which move in a lateral direction from the passageway connecting the mouth 0 ening and the mouthpiece opening of the evice. Preferably, the device is provided with interior spaces extending laterally on both sides of the passage connecting the two openings referred to, these extended spaces being terminated b wall constructions of material which will a sorb, or will not reflect to any extent, the sound waves which move laterally within the device. Therefore, there will be no interference between the sound waves which. travel from the mouth opening to the mouthpiece openin by sound waves which might be reflected from the walls of the passageway connecting the two openings. It will also be noted that themouth opening is comparatively near to the mouthpiece opening, so that the lips of the speaker may be brought within the required distance of the mouthpiece.

An object of the invention is the provision of a simple and effective device of the character referred to.

Other objects of the invention consist in various combinations of parts and improved constructions, all of which will be more fully described hereinafter and particularly set forth in the appended claims.

In order that a clearer understanding of the-invention may be had, attention is here-,'

by directed to the accompanying drawings" Referring to the drawings, the device may "comprise a shell '1 made of suitable material such aspressed metal. This shell is provided with fanf oplening 2 at one side into which thefuserfof the telephone may speak and with an openin 3 by which connection may be madewith t e mouthpiece of a telephone transmitter, indicated in dotted lines at 4.

The openings 2 and 3 are preferably in alineinent with each other on opposite sides of the device, midway of the length thereof.

The shell of the device may be formed in any suitable way as by formingthe same in several sections which may be secured to .gether to form a hollow structure which is open at the two ends. The front wall 5 of the device is preferably curved outwardly, as is shown at 6, the mouth opening 2 being formed in this outwardly curved portion of the shell. The mouth opening is preferably provided with a circular rim 7 within which the lips of the speaker may be inserted, the opening being of such a size that the lips will fit closely therein, so as to prevent to a considerable extent the entrance of foreign sounds into the opening. It will likewise be noted that with this construction the sound waves produced by the speakers voice will all enter the interior of the device, so that the voice of the speaker will be practically inaudible to a person close by. This effect is, of course, greatly increased by the interior construction of the device, whereby sound waves directed laterally within the device are absorbed to a large extent, and there is practically no vibration ofthe walls of the device, which might produce sound.

The opening 3 for the mouthpiece is preferably formed by bending the metal of the rear surface 8 of the device inwardly in the form of a short tube9, the metal comprising tube 9'being provided with a narrow inwardly directed annular flange 10. An annular'member 11 of felt or similar material is preferably positioned upon flange 10.

The telephone mouthpiece is inserted within opening 3, so that its outer edge will engage against the cushion 11, this preventing the escape of sound through opening 3 to a greater extent than otherwise would be the case. When the device has been positioned by inserting the mouthpiece into opening 3,

. it may be held in position by means of screws 12, which extend through openings in the upper and lower walls of the device into engagement with the telephone mouthpiece.

The interior space of the device is preferably provided, as stated, with lateral extensions, whereby an elongated chamber is formed at each side of the passageway connecting the mouth and mouthpiece openings. These elongated chambers are provided, as stated, with walls or surfaces of sound-absorbent material. Preferably, the soundabsorbent material is positioned at the ends of these chambers. the side walls of the chambers preferably being flared outwardly from their central portion toward the ends of the same, as is indicated at 13. Vith this construction any sound waves which impings against the side walls of the laterally extending chambers will be reflected thereby toward the sound absorbent material at the ends of the said chambers. All sound waves which do not proceed directly from the mouth opening to the mouthpiece opening and which are not necessary for the telephone transmission, are directed and reflected by the flared walls toward the said sound absorbent material, where they are wholly absorbed and prevented from further reverberating within the chamber.

The sound-absorbent material, or material which provides poor reflecting surfaces for sound waves, preferably takes the form neeaose of loosely arranged fibrous material such as felt or the like.

In the preferred construction separate open-ended members 14: are provided, which may be inserted into the device from the ends thereof, members 14 being so curved as to fit closely within the curved walls 13 of the device. Members 14 have the loose fibrous material referred to packed or positioned therein. Preferably this takes the form of a layer 15 of comparatively soft felt and a layer 16 outside the same of comparatively hard felt. The members 14 themselves may be formed of any suitable material, such for example as cardboard or the like. The layers 15 and 16 provide a sufficient thickness of sound absorbent material -to largely or wholly absorb the sound waves directed against them, a considerable thickness being required, according to my experience, to accomplish the purpose in such a device.

In the preferred construction the ends of the device are closed by cap or cover members 17, which may be removably positioned on the ends of the device. Preferably these cap members 17 are provided with side flanges 18, so that they may be positioned by simply sliding the same over the end portions of the device into position to close the ends of the device.

It will be noted that the provision of the separate members 14 containing the fibrous material tends to make the device more sanitary than it otherwise would be since these members 14 may be taken out and replaced by similar members containing fresh fibrous material. whenever desired. The fibrous material may, of course, be sprayed or impregnated whenever necessary with antiseptic fluid.

It will be observed that the'lips of the speaker, when ap )lied to opening 2, are within about one-half inch of the mouthpiece 4, in my preferred construction, which is considered by -telephone engineers to be the proper distance. It will also be observed that the outwardly curved bulge 6 of the casing, in which the mouth opening is situated, aids in producing clear articulation when the device is used. Because of this curvature, and the sharp edge to the mouth opening whichis provided, the sound waves or portions thereof which tend to travel laterally from the edges of the mouth opening are permitted to do so unimpeded, and consequently the articulation is clearer than it would be if these waves were obstructed or confined.

it will also be noted that the plate indicated at 19, bearin the subscribers number, is not hidden or obscured by the use of the device described, the curvature of the outside of the device, corresponding to the flare of the inside walls of the lateral extensions,

serving the additional function of leaving the view of the number plate unobstructed.

It willbe noted that the invention is not limited strictly to the details of construction which have been particularly described,

. but thatthe same is as broad as is indicated by the accompanying claims.

What I claim is:

1. A device of the character described,

comprising a member having a telephone mouthpiece opening, an opening to which the mouth of the user may be applied, and laterally extending .wings the side walls of which taper outwardly toward their outer ends, said member having an interior space providing a passageway between said openings and extending into said wings. 2. A- device of the character described, comprising a member having a telephone mouthpiece opening, an opening to which the mouth of the user may be applied, and an interior space providing a passage between said openings with lateral extensions, the front wall of said member having a forwardl and laterally extending protuberance in whlch said mouth opening is situated.

3. A device of the character described, comprising a member having a telephone mouthpiece opening at the rear, an opening to which the mouth of the user may be applied at the front, and an interior space providing a passage between said openings, said space having laterally extending chambers filled, fora considerable distance laterally, with-sound absorbent material, at each side of said passage.

4. A device of the character described, comprising a member having a telephone mouthpiece opening, an opening to which the mouth of the user may be applied, and an interior space providinga passage between said openings, said space having laterally extending chambers, at each side ofsaid passage, having sound absorbent material at the ends thereof, and side walls so shaped as to direct against said material all sound waves which do not enter said mouthpiece opening.

5.,A device of the character described,

comprising a member having a telephone mouthplece opening, an opening to which" the mouth of the user may be applied, and an interior space providing a assage between said openings, with laterafextensions having side walls which curve outwardly toward their outer ends, said extensions having sound absorbent material extending across their outer ends.

6. A device ofthe character described,

comprising a member having an opening for a telephone mouthpiece, and 'a mouth opening, said member having a wall structure for absorbing sound waves, comprising a layer of loose fibrous material on the infibrous material on the outer side of said first layer.

7. A device of the character described, comprising a, member having an opening for a telephone mouthpiece, and an opening to which the mouth of the user may be applied, and an interior space providing a passage between said openings, with lateral extensions, the latter having side walls which flare outwardly toward their outer en s.

8. A device of the character described, comprising a member having an opening for the telephone mouthpiece, an opening to which the mouth of the user may be applied, and an interior space providing a passage between said openings, with lateral extensions, and separate members inserted in said extensions, containing loose fibrousmaterial.

9. A device of the character described, comprising a member having an opening .for the telephone mouthpiece, an opening to which the mouth of the user may be applied, and an interior space providing a passage between said openings, with outwardly flaring lateral extensions arranged to provide unobstructed chambers for a distance at each side of said passage, and provided with sound absorbent material for a considerable distance beyond said chambers.

10. A device of the character described, comprising a member having an opening for the telephone mouthpiece, an opening to which the mouth of the user may be applied, and an interior space providing a passageway between said openings, with lateral extensions, and an end wall structure for each said extension, comprising a layer of loose fibrous material on the inside,

and a layer of harder, more compact, fibrous material on the outer side of said first layer.

11. A device of the character described, comprising a member adapted to be mounted on a telephone mouthpiece, said member having a front opening to which the mouth of the user may be applied, and a rear opening in alinement therewith for the mouthpiece, formed by bending the material of the rear side of the member forwardly to form a short forwardly extending tube within the member, having a front annular flange against which the mouthpiece may abut, said member having an interior space providing a passage between sa1d openings.

Signed at New York, in the county of New York, and State of New York, this 

